Light-emitting diodes (LEDs) have attracted growing attention in recent years as lighting sources alternative to conventional incandescent light bulbs and fluorescent lamps due to their characteristics of providing low power consumption, long-life operation, high reliability, etc. An LED, per se, serves as a small light source, and thus surface light source technology is required to evenly illuminate a broader area in order to allow it to be used for lighting. Backlighting is a well-known example of a surface light source technology. Backlighting typically requires, in part, a lens or prism which is manufactured using a complex optical design, as well as a light guide panel on which reflective dots are formed. In the course of the backlighting, light emitted from LEDs enters into a side edge of the light guide panel. The light emitted into the light guide panel travels throughout the light guide panel by constantly bouncing from the panel's boundary surfaces by a process of total internal reflection, while diffusing part of the traveling light at light diffusion spots (i.e., reflective dots), thereby allowing the light to be emitted from the front surface. Thus, the entire area of the light guide panel can be illuminated by the light emitted from the LEDs.
However, manufacturing such a conventional light guide panel requires particular processes, namely: designing optical elements depending on the dimension and/or shape of the panel, providing a precise molding, and then stamping the molding, and, accordingly, there is a lack of versatility in such manufacturing. Further, it is highly difficult to ensure design accuracy and homogeneity, and the cost of manufacturing necessarily increases thereby.